The present invention relates to a seat belt system for an automobile and more particularly to a mechanically actuated passive seat belt system.
Considerable number of vehicle passengers do not wear a seat belt, knowing the seat belt is effective in protecting the passenger during a crash of an automobile. This is because the passenger thinks it much trouble to wear the seat belt or disregards it.
For the purpose of eliminating the above-mentioned shortcoming, passive seat belt systems have been developed which are designed to automatically fasten a seat belt around a passenger in a seat when a vehicle door is closed.
Among these systems of the passive type a group of systems is known wherein a seat belt is fixed at one end thereof to a retractor mounted to a floor within a vehicle body adjacent the inboard side of a seat and is fixed at the other end thereof to a door sash at an area adjacent the rear and upper edge, so that when the door is opened, the seat belt will extend forwardly of the seat to allow easy ingress or egress of a passenger and, the passenger sits on the seat and then closes the door, the seat belt is automatically fastened around the passenger.
Another group of systems, which is also known, employs an electrical or pneumatic means for displacing a guide, through which a portion of a seat belt passes, forwardly along a roof side of a vehicle body, in response to opening movement of a vehicle door.
A problem with the former group is that the safety belt cannot fasten the passenger with a sufficient force when the door is closed owing to the fact that the end of the seat belt is fixed to the rear edge of an upper sash of the door. With this arrangement, furthermore, a sufficient amount of forward displacement of the seat belt away from the passenger cannot be obtained when the door is opened.
The latter group has a problem too that the construction is complicated and adds to price hike.